Strategic single point mutation yields a solvent- and salt-stable transaminase from Virgibacillus sp. in soluble form

Guidi, Benedetta; Planchestainer, Matteo; Contente, Martina Letizia; Laurenzi, Tommaso; Eberini, Ivano; Gourlay, Louise J.; Romano, Diego; Paradisi, Francesca; Molinari, Francesco

Abstract

A new transaminase (VbTA) was identified from the genome of the halotolerant marine bacterium Virgibacillus 21D and its expression resulted in the production of an insoluble protein in E. coli. After a single mutation identified through sequence homology analysis, the mutant VbTA T16F was successfully expressed as a recombinant protein and characterised. VbTA T16F showed high stability towards polar organic solvents and salt exposure, accepting mainly hydrophobic aromatic amine and carbonyl substrates. The 2.0 Å resolution crystal structure of VbTA T16F is reported, and together with computational calculations, revealed that this mutation is crucial for correct dimerisation and thus correct folding, leading to soluble protein expression.

• Journal Article Type: Article
• Publication Date: Dec 1, 2018
• Journal: Scientific Reports
• Print ISSN: 2045-2322
• Electronic ISSN: 2045-2322
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 1
• Article Number: 16441
• APA6 Citation: Guidi, B., Planchestainer, M., Contente, M. L., Laurenzi, T., Eberini, I., Gourlay, L. J., …Molinari, F. (2018). Strategic single point mutation yields a solvent- and salt-stable transaminase from Virgibacillus sp. in soluble form. https://doi.org/10.1038/s41598-018-34434-3
• DOI: https://doi.org/10.1038/s41598-018-34434-3
• Publisher URL: https://www.nature.com/articles/s41598-018-34434-3